The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

A portion of the old Pirates stadium over which a defining home run once flew still stands even after the rest of the stadium was torn down.

The last remnants of Fort Pitt also hold the distinction of being the oldest structure west of the Allegheny Mountains.

This permanent exhibition celebrates the finest of our heartless automatons both real and fictional.

This university transit system is a 1970's vision of the future.

America's post-nuclear-attack chambers of Congress.

The world's largest fully steerable radio telescope.

This rural community has attracted both scientists and techno-refugees due to its federally-mandated lack of technology.

This abandoned train tunnel has been the subject of countless ghost stories for years.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

A retired subway car stands alone in a field in the middle of Queens.

This futuristic airport terminal was abandoned for decades before reopening as a hotel—with a vintage plane of its own parked out back.

The oldest continuously operating farm in New York State.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

If it hadn't been caught in time, a flaw in the design of this Manhattan skyscraper could have led to its collapse.

The 28-foot granite map plots the locations of 40 theaters in New York City.

A quick trip around the globe through an amazing miniature exhibit.

Fake subway tiles were installed to cover a design that resembled the Confederate flag—it's unclear if the resemblance was intentional.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

This diesel train serviced the Brooklyn waterfront for more than three decades.

Elevated freight railway turned wildly successful urban park.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

This no man's land slicing through the island is strewn with abandoned relics of another time.

The ancient mosaics here are considered among the finest in the world, and serve as a stunning record of Greco-Roman daily life.